Interview BD

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AppifyLab Ltd ​

Company Websitehttps://www.appifylab.com/
Career Websitehttps://www.appifylab.com/career
Technologies UsedReact, Flutter, Vue, Laravel, Nuxt, NodeJS

Introduction ​

Appify lab has a LMS(Learning Management System) product name EzyCourse

Interview Stages ​

Initial Online Contest ​

Platform: vJudge
Details: Participated in an online coding contest.
Selection: Out of numerous participants, around 40-50 were selected for the onsite contest.

Onsite Contest ​

Selection: Out of numerous participants, around 10-15 were selected for the final interview.
Details: The onsite contest was held in Sylhet.

Final Interview ​

The final interview is mainly a discussion about the company and the candidate's interest in joining. Employment terms like probabtion periond, internship time, possibility of permanent position, and location were discussed.

First Round Questions ​

The given questions are the summarized version of the original questions. The original questions are available in the Online Round Problem Set.

Given multiple test cases, each containing a 3-letter string (uppercase/lowercase letters), you have to check whether the string equals "YES", case-insensitively. Output "YES" if it matches, else "NO".

Show Answer
cpp
# include<bits/stdc++.h>
using namespace std;

int main() {
    int t; cin >> t; // number of test cases

    while (t--) {
        string st; cin >> st;  // read input string

        // convert input string into lowercase
        for (auto &c: st) {
            c = tolower(c);
        }

        // if input string equals yes, the result is YES, otherwise NO
        (st == "yes") ? cout << "YES\n" : cout << "NO\n";
    }

    return 0;
}

Given

  • Number of students, games, and connection events
  • For each student, the game they like
  • A sequence of connections between pairs of students over time

For each game, determine the earliest time when all students who like that game become connected (either directly or indirectly). Output -1 if they never get connected.

Given:

  • Number of questions
  • For each question: initial score, per-minute penalty, minimum score
  • For each question: submission time and number of submissions (positive if solved, non-positive if unsolved)

Calculate the total score based on a formula involving penalties and number of attempts. If a question is unsolved, its score is 0.

Given a list of unique 9-digit phone numbers. For each phone number, find the shortest digit substring that uniquely identifies it (i.e., no other number contains it as a substring).

Given:

  • Number of dishes, adults, and kids
  • For each dish: happiness value if eaten by an adult or by a kid

Assign one dish to each person (adult or kid) to maximize the total happiness. An adult eats the entire dish; a kid partially eats it.

Given:

  • A list of item costs
  • A limit on the total increase Sabbir can apply to the item costs

Sabbir increases item costs (total increment ≤ limit) to minimize the final score difference in a turn-based game where players pick items alternately and optimally.

Given:

  • A circular string of length N×K representing N fragments of length K
  • A list of G candidate fragments (all distinct)

Determine if the circular string can be split into a sequence of N valid fragments (from the candidate list) in some rotation. If possible, output any such valid sequence.

Given multiple test cases, each with two numbers: total artifacts n and a position k. Artifacts are arranged in a special sequence: first all odd-numbered ones, then multiples of odd numbers (2×odd, 3×odd, etc.) in order, skipping duplicates. Find which artifact appears at position k.

Given grid dimensions n × m. Determine if it is possible to assign pigment values to rows and columns such that every cell in the grid (combining row and column pigment modulo nm) has a unique value. If possible, output the row and column pigments.

Second Round Questions ​

The given questions are the summarized version of the original questions. The original questions are available in the Final Round Problem Set.

Given a sequence of integers, convert each number to binary using parity (even → 1, odd → 0), concatenate to form a binary string, and print it with leading zeros removed.

Show Answer
cpp
#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n; cin >> n;    // size of the array

    // read input array
    vector<int> arr(n);
    for (auto &x : arr) cin >> x;

    // convert even -> 1, odd -> 0
    for (int i = 0; i < n; i++) {
        arr[i] = (arr[i] % 2 == 0) ? 1 : 0;
    }

    // find position of the last leading zero (if any)
    int initial_zero = -1;
    for (int i = 0; i < n; i++) {
        if (arr[i] == 0) {
            initial_zero = i;
        } else {
            break;
        }
    }

    // Build answer string from remaining elements
    string ans;
    for (int i = initial_zero + 1; i < n; i++) {
        ans += char(arr[i] + '0');
    }

    cout << ans << "\n";
}

int32_t main() {
    ios::sync_with_stdio(0);
    cin.tie(0);

    int t; 
    cin >> t;  // number of test cases

    for (int i = 1; i <= t; i++) {
        cout << "Case " << i << ": ";
        solve();
    }

    return 0;
}

Given dimensions of two rectangles, one inside another, where the outer rectangle is (A×B) and inner rectangle is (C×D), with C ≤ A and D ≤ B.

Compute the area between the two rectangles modulo 1,000,000,007.

💻 Submit Code

Show Answer
cpp
#include<bits/stdc++.h>
using namespace std;

const int mod = 1e9 + 7;

long long multiplication(long long a, long long b,long long m){
    a %= m;
	b %= m;
	return (a * b) % m;
}


void solve(){
    long long a, b, c, d; cin >> a >> b >> c >> d;

    long long x = multiplication(a, b, mod);
    long long y = multiplication(c, d, mod);

    long long result = (x - y + mod) % mod;
    cout << result << "\n";
}
 
int32_t main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    cin >> t;
    for(int i = 1; i <= t; i++){
        solve();
    }
    
    return 0;
}

Given N baskets arranged in a circle with given apples in each and a number K indicating how many apples one will eat.

Simulate the person moving right and eating apples if present, and output the number of apples left in each basket after exactly K apples are eaten.

Given a string s of length n. Pick an integer k (1 ≤ k ≤ n) and perform a transformation: reverse each substring of length k sliding through the string, and find the lexicographically smallest resulting string. Output that string and the smallest such k.

💻 Submit Code

Given a simple directed graph with N vertices and M edges. Count how many vertices can be starting points for infinite walks (i.e., they lie on or can reach a cycle).

💻 Submit Code

Given a book with N pages (numbered 1 to N) and a secret digit (0–9), and you randomly pick a page. Compute the probability that the page number you picked contains the secret digit, expressed as an irreducible fraction P/Q.

💻 Submit Code

Given Grid size n×m and manhattan distances from a hidden cell (a, b) to (1, 1) and (1, m). Find the coordinates (a, b) of the hidden cell using the given distances

💻 Submit Code

Contributors ​